Might this be sunburn? I have my Lemon Tree in full sun and have overwintered it inside for the past two Winters. I have yet to see one lemon. I can't figure out what I'm doing wrong. Any ideas?

It looks like it might be sunburn. After wintering indoors, you should move your tree slowly to full sun. This means a few days outside in the shade, then a slow progression to full sun. A two week job.

Your lemon should start producing fruit between 3 - 4 years of age but it could take 10 years.

Thank you. I was careful about the transition period (last year's lesson). The brown scalded areas just started appearing about two weeks ago. I honestly don't know how old the plant is. I purchased it from Home Depot 3 years ago in an 8" pot. It had one small creamy white blossom on it which promptly fell off a week or so after I brought it home.